Lead alloy



UNITED STATES PATIENT, orrlca.

enonen n. WOBRALL, or xmxwoon, mssouar, Assrcmon T0 UNITED man coirn. Y., A coarona'nou or NEW :rnnsn'z.

ran, on new man,

LEAD ALLOY.

Specification of Letters latent.

No Drawing. Application filed August 11.1919, Serial .No. 316,808. Renewed May 28, 1920. Serial No. 885,084. a

To all whom it may concern: I

Be it known that GEORGE H. WoRRALL', United States citizen, residing in Kirkwood, Missouri, has invented the following described Improvements in Lead Alloys.

My invention consists in a hard lead alloy suitable for machine bearings and like purposes, and containingllead, magnesium and mercury with or wit out other ingredlents. I-have discovered that mercury exercises a hardening effect on lead alloyed with certain of the lead-hardening metals such as magnesium and that it may be used for this purpose with economy and general improvement in the product alloy.

My new alloy is made substantially as follows:

To a quantity of molten lead there is added in any suitable manner an amount of magnesium constituting from, say one-half of one per cent. to three per cent. of the product. This alloy if allowed to cool will be found to possess a certain de ree of hardness according to the known e ect of magnesium on lead. To this alloy I add either in the same vessel or elsewhere a small percentage of mercury generally less than 2% i and the resulting alloy is then cast into ingots read for sale.

The ad ition of the mercury raises the resulting hardness and improves the fluidity of the allo when molten. Variation in the amount a ded produces corresponding various degrees of resulting hardness. My'

alloy thus preferably consists of lead upward of 90%, magnesium 2% or less, mar-- Patented Nov. 30,1920.

cury 2% and preferably about 5%. Other metals may be added when desired to give special effects to the product, aluminum beinga useful addition for preventing drossing of the alloy when molten, and when aluminum is introduced it is added in small amounts less than 1%, althoughstill larger quantities of aluminum or other metals such as zinc or tin can be used so far as they do not impair the usefulness of the alloy for the purposes intended. Such additions will naturally proportion-of lead, which for general 'bearln'g-metal purposes should ordinarily be as high as possible. In such alloys, with or without other metals, the use of mercury enables a desired degree of hardness to be attained with the use of less magnesium than would otherwise be required, and hence at less expense of manufacture.

Claims.

1. A hard lead alloy suitable for bearin s and like uses comprising a main body of lea 2% or less of magnesium and 2% or less of mercury. v

2. A hard'lead' alloy suitable for bearings and like uses comprising upward of 90% lead, 2% or less of magnesium and about .5% of mercury.

In testimony whereof, I have signed this specification.

GEORGE H. WORRALL.

be made at the sacrifice of the 

